System and method for sending pictures over telephone lines



L. H. CROOK Nov. 26, 1940.

SYSTEM AND METHOD FOR SENDING PICTURES OVER TELEPHONE LINES Filed Nov. 18, 1937 YVU L-HCRack alkali/M41154 Patented Nov. 26, 1940 UNITED STATES PATENT OFFICE SYSTEM AND METHOD FOR SENDING PIC- TUBES OVER TELEPHONE LINES Louis H. rook,. Washington, D. 0., assignor to The Second National Bank of Washington, Washington D. C., trustee Application November 18, 1937, Serial No. 175,309

2 Claims. (Cl. 1'78-5.6)

My invention relates to television, and more operation room or rooms in this station are meespecially to a method or system of sending pictallically lined as at ll so that all instrumentaltures b wire ities are completely metallically shielded. With- One object of my invention is to prevent the in the metallic lining or casing H is located a distortion, by static interferences, of images, conventional telephone panel indicated generally 5 whether still or in motion, sent over wires. at 9 and a television sending instrument indi- Another object is to provide a practicable and led generally by the numeral l2. A convensuccessful means for sending pictures over teletional television instrument connected to a transphone or telegraph wires without interruption of mission system is shown in Tanimoto Patent 10 sound messages when sent simultaneously with 1,769,608 of July 1930, and no claims are di- 10 th i t rected herein to the television apparatus per se.

Attempts have heretofore been made to use tel- From t e te phone sending panel 9 a bundle l3 ephone wires for the transmission of picture sigof the telephone wires, individually insulated, is nals, but they have not been successful, princitaken out and collected in the c m [4. Thi

pally because of the distortion of the images due p ses a metal shielding 0 ad p p 15 to interference from external earth static. By p et y surrounding the t p e es This means of my invention such interferences are abet pipe s t y jo ned as at l5 to the metalsolutely prevented, and the transmission of per- 0 lin ng ll of the station house so that no leakfect pictures assured regardless of external elecage of electric current is possible around the t i 1 diti end of the cable I or elsewhere along the line, as 20 In order now to prevent such interference, long as a Comp ete e d g, is p ovided in accausing distortion of the pictures and interrupooldanoe With the p e t vention, and Withtion of the sound messages, I provide a complete out grou d shielding, not only of the wires and the instru- The le, nless n un er r un conn tio mentalities employed for sending and receiving is taken alo t ep e p s, in the usual :5 sound messages and pictures, but also of the ends and hung under a suspension W is y of the wires where they are joined to said instrups ll. One such po e I3 s soo in and 1nenta.1jtj es In other Words I k use of 1 on the same is secured a control or distributor or lated, electric transmission lines, complete in switching hOX i9, shoWh in a r s e in themselves for sending telephone or telegraph This box s p e y lined y pp or other 30 messages, or delivering light or electric energy, m t c plate 20, and to this lining the other as one conductor for picture transmission, while end of the lead cable I4 is tightly jo ed as at the complete metallic shielding or covering con- 25 to preve t l possibility of Current ea e stitutes the second conductor for the picture between the cable and the lining 20 of the box.

transmission. The telephone wires in the bundle l3 are now 5 One embodiment of my invention is illustrated carried from the telephone panel 9 at the sending in the accompanying drawing, wherein: station Ill through the lead or metal cable M and Fig. 1 is a diagrammatic view of a telephone into the metal lined box IS on the pole I8. From line between a sending station and a number of there the individual conductors 22 connect with receiving stations; the several receiving stations in the houses 23 to 40 Fig. 2 is a vertical section of a distributor box H, which the distributor boX I9 is intended to as used for heavy cables with many wires; serve. Preferably all of the insulated conductors Fig. 3 is an elevation and partial section of the pass out from the metal lined distributor box l9 sending station equipped both with telephone through metal pipes 28, soldered or otherwise and television apparatus; and firmly attached to the metal lining 20 of the dis- 45 Fig. l is a vertical view showing the lead-in tributor box Hi. All of these telephone conducfrcm the distributor box to the receiving station tors 22 are of the ordinary, insulated kind. for transmission of both pictures and verbal Supposing now that one of the houses, 26 for messages. instance, desires to have television transmission In the drawing the same reference characters installed, all that is then necessary is to provide 50 represent the same parts in the difierent figures. the arrangement indicated in Fig. 4, where the Referring now more particularly to Figs. 1, 2 and telephone conductors 22 are enclosed in a metal 3, numeral lil represents a central telephone statube to, one end of which is soldered or tightly tion or substation of the usual construction but secured to the metal lining 20 of the distributor also equipped for transmitting television. The box It. The other end of this metal tube 30 is similarly tightly secured to the metallic casing 3|, containing a conventional television receiving instrument indicated generally at 32 which is properly insulated at one pole from the casing and with which pole the end of an insulated telephone conductor 22 is connected. The television instrument itself, one pole of which has wire connection 39 with the casing 3|, may be of any suitable kind. Through aperture 33 in the wall of the casing the television rays are then permitted to emanate, so that a picture is projected on a screen 36 in the receiving station 26.

Numeral 35 represents a telephone box, also metallically enclosed and connected with the tube 30 by means of a metal branch pipe 34. Into the telephone box 35 a branch of the conductors 22 is taken, leading to one pole of the telephone, through the pipe into the telephone box, while the other telephone pole connects metallically with its casing 35. It will now be evident that a complete shielding or metallic covering is provided for the telephone conductor from the sending station Ill to the receiving station 26. This shielding, which is continuous without any break that might permit current leakage, consists of the following metallic parts, namely ll, I4, 2|, 20, 30, 3|, 34 and 35. This means that both the receiving telephone and the television receiving instrument, as well as all the instrumentalities at the sending station in addition to the conductors, are completely shielded.

Instead of the individual metallic casings for the receiving instruments, as at 3| and 35 of Fig. 4, a common metallic lining or casing II, as in Fig. 3, may be used, and similarly individual casings may be utilized for the sending instruments 9 and 12, Fig. 3.

The telephone messages are transmitted in the ordinary way over the conductors 22 of the bundle l3, without the aid of the metallic tubing, and it should be noted that when sending television frequencies, it makes no difference whether any or all of the telephone wires in the same cable are transmitting telephone messages at the same time as the pictures are being sent over them. As a matter of fact the telephone messages will be considerably improved and be less subject to interference on account of the complete shielding, as the wires are covered, not only the entire length from station to house, by lead pipe, but that the cable ends are also similarly protected where leaving the station and entering the house. This also avoids lightning troubles. In my present invention the television frequencies are transmitted over the telephone wires and over the lead or shielding coverings thereof.

For transmitting television over the line, use is made not only of the telephone conductors 22 of the bundle l3 but also of the enumerated metallic shielding parts for the return circuit.

In the drawing an air line has been indicated, but it is evident that my invention applies equally well to an underground line.

That the invention can also be used on telegraph lines, or on power and electric lines, independent of telephone or telegraph, will be evident from the above description. The invention is also applicable to the sending of still pictures, which may be photographically reproduced for magazines or newspapers. It is to be understood that the invention as here described is not limited to the detail of construction disclosed and shown and that these may be varied widely without departing from the spirit of the invention as defined by the claims.

I claim:

1. In a transmission system for both oral messages and television; in combination, a sending station including a television sending instrument and a telephone sending instrument, a first metallic shield arranged housing said instruments and in insulated relation to one pole of each of said instruments, respectively, a metal tube conductively connected to said first shield, a distributor box having a second metallic shield, said second shield being conductively connected to said tube, an insulated conductor in said tube and having one end thereof connected to the one pole of said instruments and having its other end in said second shield, a receiving station including telephone receiving instrumentalities, a third metallic shield housing said instrumentalities and in insulated relation to one pole thereof, a television receiving instrument at said receiving station, a fourth metallic shield housing said television receiving instrument and in insulated relation to one pole thereof, a metal tube conductively connected to said second, third and fourth shields, respectively, an insulated conductor in said last mentioned tube and arranged connecting the one poles of said receiving instrumentalities and of said television receiving instrument with the one poles of said sending instruments, said tubes being conductively connected with the other poles of said sending and said receiving instruments, respectively.

2. A shielded communication system comprising in combination, a first communication instrument, a first metallic shield shielding communication instrumentalities in said instrument, switching instrumentalities, a second metallic shield shielding said switching instrumentalities, a second communication instrument, a third metallic shield shielding communication instrumentalities in said second instrument, metallic tube means conductively connecting said first, second and third metallic shields, respectively, and insulated conductor means in said tube means conductively connecting said first and said second communication instruments through said switching means, said conductors being adapted to each form one side of a selected one of a plurality of communication circuits of which said tube forms the other side.

LOUIS H. CROOK. 

